Numerous devices have been proposed for covering apertures, such as windows or other architectural openings. Roller blinds are widely used to cover windows. Roller blinds have a flexible blind which is wound around a spring loaded winding roller at the top end of the window opening. The free end of the blind is attached to a weighted bar. A clutch mechanism in the roller locks the roller against rotation so that the weighted bar remains at a desired height. The clutch can be released, usually by pulling on the weighted bar, to allow the position of the free end of the blind to be adjusted.
The prior art teaches a great many designs for roller blinds. Most of these designs are either complicated, difficult to use or require significant maintenance to keep operational.
Other types of window covering assembly include vertical and horizontal blinds which have vertical or horizontal rigid or semi-rigid slats suspended from a cross member at the top of the opening to be covered. Prior art slatted blinds often have the problem that the slats cannot be stored compactly when the blind is retracted and thus obscure portions of the window or other opening which the blind covers even when the blinds are fully open.